EPA's air monitoring equipment and software

EPA's air monitoring equipment classifications

General condition monitors

These provide us with information on general air quality and pollution happening over a large area – they give us the ‘big picture’ about air quality. They are strategically placed around the state and they form the foundation of EPA’s monitoring network. Some are fixed and some are mobile.

Local condition monitors

These tell us about local air quality and pollution issues. They are placed in communities where there is a specific pollution concern.

Incident air monitors

These monitors are set up to respond rapidly to a major and specific pollution event. They give us immediate data about the impacts of a pollution event and are used to make decisions about what EPA and other agencies do next. Data collected by some incident air monitors is also shown on EPA AirWatch.

Air monitoring equipment that produces data for EPA’s website

For monitoring small particles – PM₁₀

TEOM – a tapered element oscillating microbalance monitor continually measures the concentration of airborne particles. It does this by collecting and weighing the particles using a very sensitive balance. TEOMs are standard across EPA’s network and meet the Australian National Standard (AS 3580.9.8–2008).

For monitoring small particles – PM_2.5

BAM – a standard beta attenuation monitor automatically measures and records airborne particles. This monitor works by collecting particles on a filter tape and measuring the reduction in beta rays travelling through the particles. From this, the concentration of airborne particles is calculated. BAMs meet the Australian National Standard (AS 3580.9.12–2013).

24-hour rolling average data collected by BAMs is used to automatically trigger cautionary health advice on EPA AirWatch.

BAMs are currently used to measure PM_2.5 at the following stations: Alphington; Footscray; Geelong South; Morwell South; Morwell East; Traralgon; Moe; and Churchill.

Portable air monitors – these use sensitive, light-scattering sensors to detect particles. These monitors produce PM_2.5 data that is usually less accurate than data collected by other types of particle monitor. The portable air monitors provide the community with a more flexible air monitoring network, which allows EPA to monitor air quality at more locations.

Portable air monitors are currently used to measure PM_2.5at the following sites: Box Hill; Brighton; Dandenong; Mooroolbark; Altona North; Melton; Point Cook; Macleod; and Wangaratta.

For measuring visibility

Nephelometer – this monitor measures the amount of particles in the air using very sensitive, light-scattering sensors (in a similar way to the portable air monitors), and calculates a visibility reduction index.

For monitoring gases

Gas analysers – these monitors are used to measure the concentrations of different gases in the air, such as carbon monoxide, nitrogen dioxide, ozone and sulfur dioxide. Each gas is measured by a different analyser.

Monitoring small particles – PM_2.5

EPA has a number of different air monitoring monitors that can be used to measure PM_2.5 levels. Some of these, such as the BAM and some portable monitors (ADRs), produce data that goes on our website. Other monitors (such as Partisols and HiVols) are used as a reference method to ensure the accuracy of EPA’s data. Some types of portable monitors (such as DustTraks) are used to respond to major pollution events.

The diagram below shows their accuracy in relation to each other.

Accuracy	Air monitoring device
More accurate	Reference method EPA uses two types of air samplers (Partisols and HiVols) to measure the concentration of small airborne particles. These devices are accepted under international standards and provide the most accurate form of data. The devices are used to ensure the accuracy of other airborne particle measurement methods, such as the BAM.
	Australian Standards method A BAM (beta attenuation monitor) meets Australian Standards instrument for measuring airborne particles. It is normally housed inside air monitoring stations. It provides reliable and accurate data.
Less accurate	Indicative method ADRs and DustTraks give a good indication of particle levels, but they are not as accurate as a BAM. They are not currently accepted in the Australian Standards and their data is indicative. These devices can be easily moved from one location to another.

Accuracy

Air monitoring device

More accurate

Reference method

EPA uses two types of air samplers (Partisols and HiVols) to measure the concentration of small airborne particles. These devices are accepted under international standards and provide the most accurate form of data. The devices are used to ensure the accuracy of other airborne particle measurement methods, such as the BAM.

Australian Standards method

A BAM (beta attenuation monitor) meets Australian Standards instrument for measuring airborne particles. It is normally housed inside air monitoring stations. It provides reliable and accurate data.

Less accurate

Indicative method

ADRs and DustTraks give a good indication of particle levels, but they are not as accurate as a BAM. They are not currently accepted in the Australian Standards and their data is indicative. These devices can be easily moved from one location to another.

Air pollution modelling software

The air pollution model currently approved for regulatory purposes in Victoria is the AERMOD air pollution model. The AERMOD model is also supported by the United States Environmental Protection Agency (USEPA).

AERMOD must be used in accordance with the requirements set out in the State Environment Protection Policy (Air Quality Management) Schedule C (PDF). EPA has guidelines on the recommended use of AERMOD: